31st October 1993 was a Sunday.
October 31, 1980, was a Friday.
January 31st, 1939 was a Tuesday.
In order to know what day of the week a day in February 1985 was one needs to know the date in February.
February 29th, 1985 was actually a leap year. So, this day of the week did not occur.
December 31st, 1985 fell on a Tuesday.
31st May 1960 was a Tuesday.
May 31st, 1941 fell on a Saturday.
May 31st, 1974 fell on a Friday.
May 31st, 1986 fell on a Saturday.
Sunday
It was a Thursday.
31st May 1975 was a Saturday.
May 31, 1965, was a Monday.
May 31st, 1957 fell on a Friday. The following year, May 31st fell on a Saturday.
May 15 1985 was a Wednesday.
May 25, 1985, was a Saturday.